Boulder River at Big Timber Mount
USGS Site No: 06200000 • Boulder River • Sweet Grass County, MT
Boulder River at Big Timber Mount on the Boulder River is currently at 2,340 cfs (Very High — 149th percentile for this date) . Gage height: 4.26 ft.
Reading from
Historical Percentile Comparison
Today's discharge compared to the long-term record for October 28 at this station. Percentile rank shows what fraction of historical years had lower flow on this date.
| Percentile | Label | CFS Threshold | Today's Flow |
|---|---|---|---|
| 10th | Very Low threshold | 136 | |
| 25th | Low threshold | 173 | |
| 50th (Median) | Normal (median) | 211 | |
| 75th | High threshold | 249 | |
| 95th | Very High threshold | 364 |
30-Day Hydrograph
Recent discharge plotted against the historical 10th–95th percentile envelope for the same calendar days. Source: USGS daily values + long-term statistics.
30-Day Flow History
| Date | Discharge (CFS) | Gage Ht (ft) |
|---|---|---|
| May 28, 2026 | 2,180 | — |
| May 27, 2026 | 1,640 | — |
| May 26, 2026 | 1,260 | — |
| May 25, 2026 | 811 | — |
| May 24, 2026 | 563 | — |
| May 23, 2026 | 518 | — |
| May 22, 2026 | 577 | — |
| May 21, 2026 | 646 | — |
| May 20, 2026 | 651 | — |
| May 19, 2026 | 722 | — |
| May 18, 2026 | 850 | — |
| May 17, 2026 | 1,030 | — |
| May 16, 2026 | 1,210 | — |
| May 15, 2026 | 1,500 | — |
| Apr 20, 2026 | 361 | — |
| Apr 19, 2026 | 372 | — |
| Apr 18, 2026 | 387 | — |
| Apr 17, 2026 | 405 | — |
| Apr 16, 2026 | 426 | — |
| Apr 15, 2026 | 424 | — |
| Apr 14, 2026 | 440 | — |
| Apr 13, 2026 | 470 | — |
| Apr 12, 2026 | 458 | — |
| Apr 11, 2026 | 410 | — |
| Apr 10, 2026 | 376 | — |
| Apr 9, 2026 | 365 | — |
| Apr 8, 2026 | 344 | — |
| Apr 7, 2026 | 329 | — |
| Apr 6, 2026 | 324 | — |
| Apr 5, 2026 | 329 | — |
Station Information
- USGS Site No
- 06200000
- State
- MT
- County
- Sweet Grass County
- Coordinates
- 45.8338, -109.9387
- Drainage Area
- 525 mi²
- Datum (ft)
- 4,056.3
- HUC Code
- 10070002
Flood Stage Thresholds
- Flood Stage
- 8.0 ft
Currently 3.74 ft below flood stage.
Recent Extremes
- Max discharge
-
4,900 cfsJun 2, 2025
- Min discharge
-
80 cfsSep 15, 2025
- Days at flood stage
- 0
Computed from the local daily-values archive.
Nearby Gauges
-
East Boulder River below Dry Fork Creek near Mcleod, MountVery High23.3 mi · 347 cfs
-
Shields River near Livingston MountVery High26.9 mi · 274 cfs
-
Stillwater River Near Absarokee, MountVery High32.3 mi · 3,280 cfs
-
Yellowstone River Near Livingston, MountVery High34.4 mi · 11,600 cfs
-
Shields River below Sf Shields River near Wilsall, MountUnknown35.2 mi · 203 cfs